Documentation: remove duplicated words

Remove many duplicated words under Documentation/ and do other small
cleanups.

Examples:
        "and and" --> "and"
        "in in" --> "in"
        "the the" --> "the"
        "the the" --> "to the"
        ...

Signed-off-by: Paolo Ornati <ornati@fastwebnet.it>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt
index a60f3ce..994355b 100644
--- a/Documentation/memory-barriers.txt
+++ b/Documentation/memory-barriers.txt
@@ -670,7 +670,7 @@
 
 
 In the above example, CPU 2 perceives that B is 7, despite the load of *C
-(which would be B) coming after the the LOAD of C.
+(which would be B) coming after the LOAD of C.
 
 If, however, a data dependency barrier were to be placed between the load of C
 and the load of *C (ie: B) on CPU 2: